• Journal of the Korean Ceramic Society
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• v.31 no.7
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• pp.804-812
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• 1994

Stable PZT coating sol was prepared using chelating agent, ethylacetoacetate(EAcAc) by sol-gel processing under ambient atmosphere. Through FT-IR spectrum analysis on solution of each reaction step, formation of metal complex was confirmed and prepared PZT sol was stable over several months. Through TG-DTA, XRD, FT-IR spetrum analysis of PZT gel powder, it was understood that the addition of EAcAc could reduce the transition temperature to ferroelectric phase, due to the increased homogeneity by matching the hydrolysis and condensation rates by chelation. Single perovskite phase was obtained by the heat-treatment at 54$0^{\circ}C$ for 30 min. The film was coated on ITO-coated glass substrate by dip coating method. After heat-treatment, PZT thin film had thickness in the range of 20~130 nm. The maximum dielectric constant of its thin film at room temperature and 1 kHz was 128.

• Journal of Pharmaceutical Investigation
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• v.24 no.3
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• pp.109-113
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• 1994

Effects of various formulation factors using $L_8$ orthogonal arrays with the stability of doxorubicin hydrochloride injections(DHls) were investigated. The degradation of DHI may be occured by pH, temperature, light and metal ions. It is known that DHI should be stored on refrigerated condition of $4{\sim}8^{\circ}C$ because of its unstability on the room temperature. The employed factors were sodium chloride as isotonic solution, sodium bisulfite or sodium pyrosulfite as an antioxidant, disodium edetate as a chelating agent, methyl parahydroxybenzoate as a dissolution time shortening agent, and hydrochloric acid or citric acid as a pH adjusting agent at $22^{\circ}C$. From the results of $L_8$ orthogonal arrays, an optimal formula, including sodium chloride, disodium edetate, sodium bisulfite and hydrochloric acid, was obtained and the shelf-life of the formula was determined as 560 days approximately.

• Proceedings of the Korean Radioactive Waste Society Conference
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• 2003.11a
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• pp.650-654
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• 2003

A major problem of nuclear energy is the production of radioactive wastes. Needs for more environmentally favorable method to decontaminate radioactive contaminants make the use of liqui $d^ercritical $CO_2$ as a solvent medium. In removing radioactive metallic contaminants under $CO_2$ solvent, two methods - use of chelating ligands and that of water in $CO_2$ emulsion-are possible. In the chelating ligand method, a combination of ligands that can make synergistic effects seems important. We discuss about the properties of microemulsion formed by F-AOT and that by non-ionic surfactant. By adding acid in water core, decontamination of metallic parts, soils were possible. The rate of metal surface dissolution to the microemulsion solution was measured by QCM. The possibility of recovering the surfactants after use is also mentioned.ed.

• Food Science and Biotechnology
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• v.18 no.2
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• pp.449-455
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• 2009

The antioxidant properties of water extracted polysaccharides (PW), 1%(w/v) NaOH extracted polysaccharides (PN1), and 5%(w/v) NaOH extracted polysaccharides (PN5) were assessed in this paper. PW showed good capability of scavenging $H_2O_2$, anti-lipid peroxidation, reduction power, and scavenging 1,1-diphenyl-2-picrylhydrazyl (DPPH). The maximum values were all observed at the dose of 1 mg/mL sample. As far as the antioxidant activities of PN1 were concerned, the capability of scavenging superoxide radical, chelating metal, and total antioxidation showed higher than those of PN5. When polysaccharide concentration was 1 mg/mL, the 3 index described above were attached 71.8%, 51.6%, and $446.3{\mu}M$ Trolox equivalent, respectively. With respect to PN5, higher capabilities of scavenging hydroxyl free radicals were obtained while the peak of 84.8% was observed at the concentration of 1.0 mg/mL. Moreover, the concentration-dependent influences were characterized in all cases.

• Bulletin of the Korean Chemical Society
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• v.33 no.9
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• pp.2917-2924
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• 2012

Four novel metal-organic complexes $[Cd_2(IP)_2(TBZ)_2(H_2O)_2]{\cdot}(H_2O)$ (1), $[Zn_4(IP)_4(TBZ)_4]{\cdot}2(H_2O)$ (2), $[Zn_2(BTC)(TBZ)_2(CO_2H)]$ (3), [Co(PDC)(TBZ)] (4) (where IP = isophthalate; TBZ = thiabendazole; BTC = 1,3,5-benzenetricarboxylate; PDC = pyridine-3,4-dicarboxylate) have been prepared and characterized by IR spectrum, elemental analysis, thermogravimetric analysis, and single-crystal X-ray diffraction. X-ray structure analysis reveals that 1, 2, and 3 are one-dimensional chain polymers, while 4 is a two-dimensional network polymer. The TBZ acts as a typical chelating ligand coordinated to the metal center in all complexes. The 1D chain architecture of 1 is constructed from isophthalates and cadmium atoms. A simultaneous presence of chelating, monodentate and bidentate coordination modes of IP ligands is observed in complex 2. In complex 3, the 16-membered rings are alternately arranged forming an infinite 1D double-chain structure. The 2D skeleton of 4 is formed by cobalt ions as nodes and PDC dianions as spacers, through coordination bonds. The hydrogen bonds and ${\pi}-{\pi}$ stacking play important roles in affecting the final structure where complexes 1 and 3 have 2D supramolecular networks, while complexes 2 and 4 have 3D supramolecular architectures.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.7 no.4
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• pp.733-737
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• 2006

In this paper, we report the coordination state and structure of $Zn(cyclam)Cl_{2})$ complex that was studied by the Raman spectrum and conductivity method. The complex of zinc(II) ion with 1,4,8,11-tetraazacyclotetradecane(cyclam) ligand is formed in aqueous solution. According to the Raman spectrum of $Zn(cyclam)Cl_{2})$ complex, $H_{2}O$ molecule and $Cl^{-}$ ion compete for the trans coordination site of zinc(II) ion. We also have investigated the competition effect of $H_{2}O$ molecule and $Cl^{-}$ ion by the conductivity method. On addition of 1,4,8,11-tetraazacyclotetradecane(cyclam) ligand to the aqueous $ZnCl_{2}$ solution, 2: 1 electrolyte is changed to 1:1 electrolyte. We suggest the possibility of elimination of heavy metal because of the affinity effect of macrocyclic polyamine(1,4,8.11-tetraazacyclotetradecane) for the heavy metal,.

• Preventive Nutrition and Food Science
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• v.13 no.4
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• pp.313-320
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• 2008

Efficiency of a far-infrared radiation (FIR) dryer for drying of citrus by-products (CBPs) was evaluated through their antioxidant activities. The CBPs dried through FIR were enzymatically digested by six carbohydrases (AMG, Celluclast, Pectinase, Termamyl, Ultraflo and Viscozyme) to prepare digests for evaluation of the activities. The total polyphenolic and total flavonoid contents of the digests were determined by colorimetric assays. The AMG digest was selected for the further experiments. The antioxidant potential of the digests were evaluated by DPPH, superoxide, hydroxyl and alkyl radical scavenging activities, $H_2O_2$ scavenging activity, metal chelating, lipid peroxidation inhibition and the reduction of DNA damage. The AMG digest from CBPs dried through FIR at $50^{\circ}C$ showed strong antioxidant activities in DPPH, superoxide, hydrogen peroxide, alkyl and metal chelating assays while all the digests showed strong lipid peroxidation activities. Further, enzymatic digests showed remarkable inhibitory activities against $H_2O_2$-induced DNA damage. Hence, the data obtained using different in vitro models clearly established the antioxidant potential of enzymatic digests from CBPs dried through FIR. Furthermore, they can be used as a source of natural antioxidants; hence, far-infrared radiation drying is a viable method for transforming wet CBPs into a dried form without destroying the bioactive components.

• Preventive Nutrition and Food Science
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• v.21 no.2
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• pp.110-116
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• 2016

This study was performed to evaluate and compare the antioxidant substance content and antioxidant activities of white (Superior) and colored (Hongyoung, Jayoung, Jasim, Seohong, and Jaseo) potatoes. The potatoes were extracted with 80% ethanol and were evaluated for the total polyphenol, flavonoid, and anthocyanin contents and for 1,1-diphenyl-2-picrylhydrazyl (DPPH)/2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt (ABTS) radical scavenging activity, reducing power, and ferrous metal ion chelating effect. The total polyphenol, flavonoid, and anthocyanin contents of Hongyoung and Jayoung were higher than white and other colored potatoes. All colored potato extracts, except for Jaseo and Seohong, showed higher ABTS radical scavenging activities than the general white potato extract. Hongyoung and Jayoung had the highest ABTS and DPPH radical scavenging activities. Optical density values for the reducing power of Jayoung and Jaseo at concentration of 2 mg/mL were 0.148 and 0.090, respectively. All colored potato extracts had lower ferrous metal ion chelating effect than the white potato. A significant (P<0.05) positive correlation was observed between total polyphenol content and total flavonoid content (r=0.919), anthocyanin content (r=0.992), and ABTS radical scavenging activity (r=0.897). Based on these results, this research may be useful in developing the Hongyoung and Jayoung cultivars with high antioxidant activities.

• The Korean Journal of Food And Nutrition
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• v.26 no.3
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• pp.398-403
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• 2013

To manufacture the fermented tea with hygienic quality, green tea was fermented using Bacillus subtilis, Saccharomyces cerevisiae and Lactobacillus bulgaricus and mineral composition, total amino acid content and antioxidative activity changes were evaluated during the fermentation period. Minerals detected in the fermented tea, the Ca, Fe, Zn, Mg and Mn minerals were detected. Ca and Mg are relatively large compared to other mineral content. Total amino acid content of the control was 3.57%, but total amino acid of fermented teas were higher (3.68~3.85%) during fermentation 20 days. Metal chelating activity of control was 55.11%, Metal chelating activity of the fermented tea using B. subtilis was the highest. In reducing power, O.D. value of the control was 2.27, three kinds of fermented tea were lower than that of control. The fermented teas increased lipid peroxidation inhibition compared to the blank test.

• Bulletin of the Korean Chemical Society
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• v.29 no.9
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• pp.1717-1722
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• 2008

The 70 kDa heat-shock protein (Hsp70) involved in various cellular functions, such as protein folding, translocation and degradation, regulates apoptosis in cancer cells. Recently, it has been reported that the green tea flavonoid (−)-epigallocatechin 3-gallate (EGCG) induces apoptosis in numerous cancer cell lines and could inhibit the anti-apoptotic effect of human Hsp70 ATPase domain (hATPase). In the present study, docking model between EGCG and hATPase was determined using automated docking study. Epi-gallo moiety in EGCG participated in hydrogen bonds with side chain of K71 and T204, and has metal chelating interaction with hATPase. Hydroxyl group of catechin moiety also participated in metal chelating hydrogen bond. Gallate moiety had two hydrogen bondings with side chains of E268 and K271, and hydrophobic interaction with Y15. Based on this docking model, we determined two pharmacophore maps consisted of six or seven features, including three or four hydrogen bonding acceptors, two hydrogen bonding donors, and one lipophilic. We searched a flavonoid database including 23 naturally occurring flavonoids and 10 polyphenolic flavonoids with two maps, and myricetin and GC were hit by map I. Three hydroxyl groups of B-ring in myricetin and gallo moiety of GC formed important hydrogen bonds with hATPase. 7-OH of A-ring in myricetin and OH group of catechin moiety in GC are hydrogen bond donors similar to gallate moiety in EGCG. From these results, it can be proposed that myricetin and GC can be potent inhibitors of hATPase. This study will be helpful to understand the mechanism of inhibition of hATPase by EGCG and give insights to develop potent inhibitors of hATPase.